Generating Narratives from Personal Digital Data: Using Sentiment, Themes, and Named Entities to Construct Stories

As the quantity and variety of personal digital data shared on social media continues to grow, how can users make sense of it? There is growing interest among HCI researchers in using narrative techniques to support interpretation and understanding. This work describes our prototype application, ReelOut, which uses narrative techniques to allow users to understand their data as more than just a database. The online service extracts data from multiple social media sources and augments it with semantic information such as sentiment, themes, and named entities. The interactive editor automatically constructs a story by using unit selection to fit data units to a simple narrative structure. It allows the user to change the story interactively by rejecting certain units or selecting a new narrative target. Finally, images from the story can be exported as a video clip or a collage

The Transcriptional Regulator Np20 Is the Zinc Uptake Regulator in

Zinc is essential for all bacteria, but excess amounts of the metal can have toxic effects. To address this, bacteria have developed tightly regulated zinc uptake systems, such as the ZnuABC zinc transporter which is regulated by the Fur-like zinc uptake regulator (Zur). In Pseudomonas aeruginosa, a Zur protein has yet to be identified experimentally, however, sequence alignment revealed that the zinc-responsive transcriptional regulator Np20, encoded by np20 (PA5499), shares high sequence identity with Zur found in other bacteria. In this study, we set out to determine whether Np20 was functioning as Zur in P. aeruginosa. Using RT-PCR, we determined that np20 (hereafter known as zur) formed a polycistronic operon with znuC and znuB. Mutant strains, lacking the putative znuA, znuB, or znuC genes were found to grow poorly in zinc deplete conditions as compared to wild-type strain PAO1. Intracellular zinc concentrations in strain PAO-Zur (Δzur) were found to be higher than those for strain PAO1, further implicating the zur as the zinc uptake regulator. Reporter gene fusions and real time RT-PCR revealed that transcription of znuA was repressed in a zinc-dependent manner in strain PAO1, however zinc-dependent transcriptional repression was alleviated in strain PAO-Zur, suggesting that the P. aeruginosa Zur homolog (ZurPA) directly regulates expression of znuA. Electrophoretic mobility shift assays also revealed that recombinant ZurPA specifically binds to the promoter region of znuA and does not bind in the presence of the zinc chelator N,N′,N-tetrakis(2-pyridylmethyl) ethylenediamine (TPEN). Taken together, these data support the notion that Np20 is the P. aeruginosa Zur, which regulates the transcription of the genes encoding the high affinity ZnuABC zinc transport system

Embedded-Cluster Calculations in a Numeric Atomic Orbital Density-Functional Theory Framework

We integrate the all-electron electronic structure code FHI-aims into the general ChemShell package for solid-state embedding (QM/MM) calculations. A major undertaking in this integration is the implementation of pseudopotential functionality into FHI-aims to describe cations at the QM/MM boundary through effective core potentials and therewith prevent spurious overpolarization of the electronic density. Based on numeric atomic orbital basis sets, FHI-aims offers particularly efficient access to exact exchange and second order perturbation theory, rendering the established QM/MM setup an ideal tool for hybrid and double-hybrid level DFT calculations of solid systems. We illustrate this capability by calculating the reduction potential of Fe in the Fe-substituted ZSM-5 zeolitic framework and the reaction energy profile for (photo-)catalytic water oxidation at TiO2(110).Comment: 12 pages, 4 figure

The adsorption of Cu on the CeO2(110) surface

We report a detailed density functional theory (DFT) study in conjunction with extended X-ray absorption fine structure (EXAFS) experiments on the geometrical and local electronic properties of Cu adatoms and Cu(II) ions in presence of water molecules and of CuO nanoclusters on the CeO2(110) surface. Our study of (CuO)n(=1,2&4) clusters on CeO2(110) shows that based on the Cu–O environment, the geometrical properties of these clusters may vary and their presence may lead to relatively high localization of charge on the exposed surfaces. We find that in the presence of an optimum concentration of water molecules, Cu has a square pyramidal geometry, which agrees well with our experimental findings; we also find that Cu(II) facilitates water adsorption on the CeO2(110) surface. We further show that a critical concentration of water molecules is required for the hydrolysis of water on Cu(OH)2/CeO2(110) and on pristine CeO2(110) surfaces

Adsorption of formate species on Cu(h,k,l) low index surfaces

We report a density functional theory study on the relative stability of formate species on Cu(h,k,l) low index surfaces using a range of exchange-correlation functionals. We find that these functionals predict similar geometries for the formate molecule adsorbed on the Cu surface. A comparison of the calculated vibrational transition energies of a perpendicular configuration of formate on Cu surface shows an excellent agreement with the experimental spectrum obtained from inelastic neutron spectroscopy. From the calculations on adsorption energy we find that formate is most stable on the Cu(110) surface as compared to Cu(111) and Cu(100) surfaces. Bader analysis shows that this feature could be related to the higher charge transfer from the Cu(110) surface and optimum charge density at the interfacial region due to bidirectional electron transfer between the formate and the Cu surface. Analysis of the partial density of states finds that in the –5.5 eV to –4.0 eV region, hybridization between O p and the non-axial Cu dyz and dxz orbitals takes place on the Cu(110) surface, which is energetically more favourable than on the other surfaces